sceusterius



0. A. SCHUSTERIUS. Piano Sounding Board.

(No Model.)

Patented Jan. 18 1-881. u y.-% I? WITNESSES I ATTORNEY N. PETERS. PHDTO-LITHOGRAPHER. WASHINGTON. o. D,

UNITED STATES PATENT OFFICE.

CARL A. SGHUSTERIUS, OF K(ENIGSBERG, PRUSSIA, GERMANY.

PIANO SOUNDlNG-BOARD.

SPECIFICATION forming part of Letters Patent No. 236,847, dated January 18, 1881.

Application filed June 17, 1880. (No model.)

To all whom it may concern:

Be it known that I, CARL ALEXANDER SOHUSTERIUS, residing atthe city of Koenigsberg, in the Kingdom of Prussia, German Empire, have invented Improvements in Sounding-Boards for Piano-Fortes, of which the following is a specification.

This invention relates to an improved sounding-board for square, upright, and grand pianos, by which the volume of sound is uniformly equalized over the entire frame of the piano, and at the same time such portions of the frame which are at present not utilized brought into action for sounding purposes.

The invention consists of a sounding-board for piano-fortes, provided with supplementary sounding-boards, which are connected with the main sounding-board by bridge-pieces in such a manner that the equalization of the volume of sound is obtained.

In the accompanying drawings, Figure 1 represents a front elevation Fig. 2, a vertical transverse section on line a 00, Fig. 1; and Fig. 3, a rear elevation of my improved sounding-board as used in upright pianos.

Similar letters of reference indicate corresponding parts.

In the drawings, G represents the main sounding-board, and D D the supplementary sounding-boards, the latter being arranged in that part of the frame outside of the main soundin g-board which was heretofore not utilized for any special purposes. The exterior lines of the main sounding'board are indicated by dotted lines in Figs. 1 and 3, the portions outside of the dottedlines forming the supplementary sounding-boards. All the soundingboards rest on thin bearing-strips (l at their extremities, which are of corresponding shape at the arc-shaped contours of the boards, as shown in Fig. 2, said strips being secured to the transverse braces R of the string-frame.

The supplementary sounding-boards D D are connected with the main sounding-board G by means of bridge-pieces B, which are shown in Figs. 2 and 3, and which are attached by screws on to tapering-cross-strips F, that are glued to the rear side of the sounding-boards O, D, and D, the cross-strips crossing the fibers of the wood as nearly as possible at right angles thereto. By this connection of the supplementary sounding-boards with the main sounding-board the volume of sound of the instrument is equalized over the entire instrument, especially when the bridgepieces are connected to the points of the main sounding-board, where the greatest volume of sound is produced.

At some points itis necessary to cut grooves or recesses into the braces It for the bridgepieces B wherever they cross the braces, as shown in Figs. 2 and 3.

To prevent the contact of the main soundin g-board with the edge-piece of the frame E, the braces are provided with pins a, Figs. 1 and 3, upon which the edge-piece rests. The edge-piece of frame E is connected by screws 11 with the braces, as shown in Figs. 1 and 2. Recesses or openings in the soundingboard 0 serve for the passage of the pins and screws without forming contact therewith.

The drawings show the application of the supplementary sounding-boards to an upright piano; but it is obvious thatthe same arrangement may be used with equal advantage for square and grand pianos.

Having thus described my invention, I claim as new and desire to secure by Letters Patent.-

1. In a piano-forte, the combination, with a main sounding-board, of one or more supplementary sounding boards arranged in the parts of the frame outside of the main sounding-board, and of bridge-pieces, which extend back of the frame from the main to the supplementary sounding-boards, substantially as and for the purpose set forth.

2. In a piano-forte, the combination, with a main sounding-board, of one or more supplementary sounding-boards, which are connected by bridge-pieces, secured to tapering rear strips of the sounding-boards, substantially as specified.

3. In a piano-forte, the combination of the main and supplementary sounding-boards G D D, resting on end strips, (1, with the frame E and braces R, the frame being connected by intermediate bearing-pins, a, and fasteningscrews 11, substantially as described.

In testimony whereofl have signed my name to this specificationin the presence of two subscribing witnesses.

. CARL ALEXANDER SOHUSTERIUS.

Witnesses:

OTTO LURBEGK, N. GULroH.

IOO 

